Roasting-furnace.



, UNTTED sTATEs PATENT OEEIOE.

- My invention relates to furnaces for roasting ore; and it consists in combining with the furnace means for injecting under pressure jets of air or air andsteam under pres'- sure 1n such manner as to prolong the life of the furnace and secure a better combustion, as fully set forth hereinafter and as illustrated in the accompanying drawings, in` *Which- Figure 1 is a transverse vertical section of a roasting-furnace embodying my improvement. Fig. 2 isa sectional plan on the line 2 2*, Fi 1. Fig. 3 is an enlarged section showing t e arrangement of parts for projecting one of the jets into the furnace.

The furnace has'. within its walls a long chamber Xwith an arched top and at intervals are fireboxes A, each with a grate B and ashit. .An arched flue Y communicates wit the fire-box and with the top of the chamber X and conducts thereto the products of combustion for roasting the ore. rIhe furnace also has an ore-receptacle F, suitably formed to supportthe body of ore to be treated and communicating with the firebox throughan opening or passage C, the top of the receptacle F being preferably curved to deflect the gases toward thebody of ore.

Within such furnaces as usually vconstructed there are metallic portions or castings, (indicated in the drawings by the letter a,) with metallic portions and rabble-shafts passing through said portions, and heretoforev one of the great drawbacks of these furnaces and of all other furnaces using iron arts to sup ort the brickarch has been the iieating of t ese iron' parts by .the gases, which are driven from the fire-boxes with such force Vthat they strike against the far side of the furnace bel fore theyl are deflected up the roasting-chamber by t This impinging of the flame against the metallic vportionsl of the furnace has caused these metallic portions to burn and warp, necessitating frequent repairs. To avoid this result and to secure a more'thorough combustion of the gases, I provide means vwhereby the course of the heated gases proi v ,Specification of Letters Patent. ,f Appiimion'med February 21.71906. seriaiNo. 302.286.

e natural draft of the furnace itself.v

Patented July 31,1906.

jected downward from the flues Y may be controlled or directed so that they are carried away from direct action upon the metallic portions by jets of a gas containing oxygen under pressure and so as to supply an additional quantity of oxygen under pressure, which will insure a more perfect combustion. As shown, this result .is secured-by forming openings s in one of the walls of each flue of the furnace and extending into each opening a nozzle o, communicating withthe steampipe T, having a control-valve l?, the nozzle o being smaller than the opening s, so that as the steam-jet is. directed from the nozzle it will carry with it through the opening s a certain proportion of air. These openings and nozzles are so arranged that the jets issuing therefrom within the furnace will cross the current of gases from the fire-box and will direct them in paths away from the vmetallic parts and into the body of hot gases in such manner as to mix thoroughly therewith and secure a thoroughcombustion thereof. Afterthe said gases have passed the bridge-wall the heaty is liberated at the point of ingress of the ases, and the latter are directed the lengt of the furnace, and a much greater heat from radiation is secured than by the ordinary flow of the gases directed by the curved tops of the flue and furnace, while the thorough combustion prevents the condensing of the gases and the formation of smoke and carbonaceous deposit.

The proj ection of the combined jets of steam and air into the body of the gases supplies oxygen thereto to such an extent that thedamper of the furnace can be closed to a f much greater degree than where the natural draft is used, and,l further, by reducing this draft the 'discharge of unconsumed gases to the flue is to a great extent reduced and great economy in fuel is secured.

Instead of steam air under pressure 'orother combustible gas may be .directed IOO IIO

away from the parts of the furnace Which or air and steam transversely ofthe said Hue,

should not be too highly heated. substantially as set forth. ro 2. The combination With the furnace hav- In testimony whereof I a'HiX my signature ing metallic portions, and rabble-shafts passin presence of tWo Witnesses. 5 ing through the same anda chamber X, Of a HERBERT W. FOX.

fireplace at the side thereof, a flue leading Witnesses: from the fireplace to the top of the furnace, MALCOLM V. WATSON, and injectors arranged to project jets of air, O. K. JOHNSON. 

